How to check if a service is set to start on boot in linux

man chkconfig for more details
Below shows me checking the start up status of the smb service, setting it to start on boot and then checking again to confirm the change.

$ chkconfig --list | grep smb
smb             0:off   1:off   2:off   3:off   4:off   5:off   6:off
$ chkconfig smb on
$ chkconfig --list | grep smb
smb             0:off   1:off   2:on    3:on    4:on    5:on    6:off